Attorneys for Katherine Jackson had asked Beckloff to decide whether she could challenge the administrators without invoking a "no contest" clause that would cause her to lose her 40 percent share of the singer's estate.

Beckloff ruled that such a challenge would not be a cause for Katherine Jackson to be disinherited. Most of Katherine Jackson's arguments for why the motion should be approved have been sealed, but Beckloff noted in his ruling that they raised several issues, including whether Michael Jackson was under "undue influence" when he signed his 2002 will.

Her attorneys did not immediately respond to an e-mail seeking comment on Friday. Katherine Jackson could argue that the men are unfit to serve, or that her son was under undue influence.

Attorneys for Branca and McClain did not challenge Katherine Jackson's petition for a ruling. If her attorneys opt to formally challenge the authority of one or both of the men, then Beckloff will convene a hearing and hear testimony.

Branca and McClain already have brokered several deals that have earned the singer's estate tens of millions of dollars. Katherine Jackson's attorneys have not objected to most of them, although they raised concerns about a deal involving concert promoter AEG Live for a memorabilia exhibit.

Beckloff ruled over Katherine Jackson's objections that the exhibit of her son's items — including some of his possessions from Neverland Ranch — could go forward.

It was revealed this week that Katherine Jackson is receiving more than $26,000 per month from her son's estate, as well as another $60,000 per month to care for her three grandchildren. Michael Jackson designated his mother as his choice to care for his children, who range in ages from 7 to 12.

Beckloff granted her permanent guardianship of the children in early August.

The money is being used to pay for a variety of living expenses and for staff to take care of the children.

While Jackson's music has sold briskly since his June 25 death and a movie based on his final concert rehearsals is due to be released in October, Jackson died heavily in debt. A former hairdresser and law firm filed creditor's claims against the singer's estate this week, totaling more $243,000.